<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>box模型</title>
    <style type="text/css">
        div{
            width: 80px;
            height: 80px;
            color: red;
        }
        #div1{
            background-color: blue;
            margin:5px;
        }
        #div2{
            margin-top:-20px;
            background-color: orange;
            padding : 5px 9px 5px;

            /*padding-top:-10px;*/
            border: 4px solid black;
        }
    </style>
</head>
<body>
<div id="div1">
div1
</div>
<div id="div2">
div2
</div>
</body>
</html>